Update theme pin and check docs build

[drammock]

About a week before a new release, make a PR that updates our pin of pydata-sphinx-theme to the theme's current HEAD commit, and do a full docs build ([circle full]). If anything looks awry, do some combination of

1. working backwards on the theme's tree until you find a commit that works/looks good on our site
2. reporting bugs to the theme (and ideally fixing them and updating the commit hash accordingly)

When you're satisifed that our dev site looks good, merge the PR with the new pin, but DO NOT CLOSE THIS ISSUE! Instead, just bump its milestone so that the process will repeat at the next release.

Places to update the pin:

• requirements_doc.txt
• sometimes in the past we've done something different in tools/circleci_dependencies.sh so double-check if a change is needed there

[larsoner]

@drammock I'm going to bump the milestone on this since I think you fixed this in #10973 and the doc build looks okay on a quick glance from me. Feel free to move back to 1.1 if you look and see problems

[drammock]

No I agree that this was dealt with for 1.1 by #10973

[larsoner]

@drammock how feasible would it be to pin to a released version? It looks like ~4 minutes is spent in every SphinxWindows Azure build to pyproject.toml build the pinned commit hash, which we should be able to skip if we use a wheel on PyPI

[drammock]

Should be ok. A new release is due in a week or two, if that matters.